1. Field
The present invention relates to a jig for a compression test in a heating furnace installed in the heating furnace to implement boundary conditions, and more particularly, to a jig for a compression test in a heating furnace in which a set of jigs are installed at upper and lower ends of a test sample to variously change boundary conditions such as a both-end hinge, a both-end fixing, or a one-end hinge and one-end fixing through simple attachment/detachment of a holder, remarkably reducing time and cost consumed to install the test sample.
2. Description of the Related Art
In general, when a building is on fire, a structural member constituting the building is exposed to a large amount of heat and is structurally weakened, making it unable to maintain its structural strength. Accordingly, when the building is on fire, the strength of the structure is decreased, causing the building to easily collapse, which frequently results in serious casualties.
Since use performance limits or structural destruction of the structural member affected by the large amount of heat upon fire of the building structure are determined according to support conditions, load states and fire-exposed surfaces as well as physical and thermal characteristics of a material constituting the building structure, it is important to perform fire-resistance design of the structure in consideration of this.
With regard to the above, the structural member is installed in a heating furnace and heat is applied to the structural member to perform a strength test so that actual fire tests and various performance test of the structural member are essentially needed.
FIGS. 1A and 1B show end fixing conditions of a test sample according to a prior art. When the test sample is in a heating test, the end fixed state can be confirmed by checking whether moment occurs from an end of the test sample according to application of a load, or measuring rotation and movement of the end of the test sample.
A typical method of implementing end fixing conditions, as shown in FIG. 1A, is performed by fixing an end of a test sample 1 to a frame 10 using bolts 12, etc., and applying a load to fix the end of the test sample 1 using a clamp 30 of a load tester. It will be appreciated that, in the end fixing conditions, both ends of the test sample 1 are fastened to the frame 10 using the bolts 12 so that rotation or deformation of the test sample 1 is restricted.
FIG. 1B shows a hinge jig 40 having a projected hemispherical shape used in a conventional compression test. In most cases, since a force application part of the load tester has a jaw shape to protect a cylinder as an actuator, the hinge jig 40 is installed at only a lower end of the test sample 1.
When the conventional hinge jig 40 is mounted and a force is applied using the clamp 30 of the load tester, provided that upper and lower ends of the test sample are hinged, even when the end of the test sample 1 is rotated to generate bending or buckling thereof, it is possible to prevent generation of moment from the end of the test sample 1.
However, the conventional jigs for a compression test have problems in that only simple fixing or hinge boundary conditions can be implemented. Therefore, different types of various jigs must be prepared according to test conditions at every time, and time and cost consumed to install the test sample are largely increased.